title: Role of the thymus in directing the development of a subset of B lymphocytes.
abstract: In an effort to evaluate the role of the thymus in influencing the development of Lyb-5- B lymphocytes, mice expressing both the xid and nu gene defects were studied. Mice expressing either of these defects respond to both trinitrophenylated Brucellus abortus and lipopolysaccharide; whereas mice with the combined defect show markedly suppressed responses. The other abnormalities included: (a) greater than 80 percent diminution of serum Ig levels; (b) significant increase in the number of sIgM+ sIgD- B lymphocytes; (c) reduced expression of IgD on sIgD+ cells; and (d) a strikingly abnormal histology of their lymphoid tissue. Because nu/nu mice that do not express the xid defect appear relatively normal, it would suggest that the development of Lyb-5- B lymphocytes require a thymic influence for normal maturation, whereas, Lyb-5+ B lymphocytes are relatively independent of such influences.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000166:cytology; D000942:Antigens, Bacterial / Q000276:immunology; D001402:B-Lymphocytes / Q000145:classification / Q000166:cytology*; D002003:Brucella abortus / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008198:Lymph Nodes / Q000473:pathology; D008213:Lymphocyte Activation; D051379:Mice; D008808:Mice, Inbred CBA; D008819:Mice, Nude / Q000235:genetics; D011947:Receptors, Antigen, B-Cell / Q000032:analysis / Q000096:biosynthesis; D013950:Thymus Gland / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D011947:Receptors, Antigen, B-Cell; D014301:Trinitrobenzenes